The burden fed into a shaft furnace, in order to achieve optimum furnace operation, must be deposited onto the charge surface, depending upon particular conditions, in a specifically arranged manner. Several types of installations have been suggested for this purpose. A charging apparatus for high pressure blast furnaces is disclosed in German Publication No. DAS 2 035 458 where, below the charge hopper, which is centrally located in the furnace hood, a rotating chute is arranged which, simultaneously, rotates and swivels. That is, the angle of discharge towards the charge surface may be varied. The chute is suspended from a swivel sleeve surrounding the charge hopper and is connected with a control lever which meshes with a second and normally synchronous swivel sleeve. In order to alter the chute angle, the second normally synchronous swivel sleeve is angled towards the first swivel sleeve. For this arrangement, there are structural parts exposed in the furnace chamber which carry out rotary movements. Special measures must be taken to protect those parts from the effects of the prevailing dust in the chamber. This is done by supplying a special sealing gas to those chambers in which the rotating parts are positioned.
German Publication No. DOS 2 104 116 discloses effecting distribution of the charge material by means of a universally flexible distributor pipe. The distributor pipe pivots on a transverse axis, and is hinged in an annular support which in turn swivels around a horizontal axis. While the swivel motion of the annular support is caused by a gear, to which at least one of the two journal bearings of the annular support is connected, thereby being out of the furnace chamber, the pivot motion of the distributor pipe housed in the annular support requires intricate mounting. A second annular support is connected to the distributor pipe above its seat in the first annular support, and may be displaced parallel with the swivel axis of the first annular support. By displacing this second annular support, it is possible to adjust the distributor pipe in the annular support within certain limits. By superimposing both movements, the distributor pipe can be aimed at any spot on the charge surface. However, the requirement of a second displaceable annular support involves complicated structure. Furthermore, it is relatively heavy.